Cost guide
How much does loft boarding cost?
Loft boarding costs £30 to £60 per square metre for a raised deck that keeps the insulation intact, plus £250 to £450 for a ladder and hatch. A typical semi comes to £600 to £1,400 all in.
Typical prices
| Work | Typical UK price |
|---|---|
| Raised loft boarding, per m² | £30 to £60 |
| Direct-to-joist boarding, per m² (only where insulation is shallow) | £20 to £35 |
| Loft ladder and hatch, fitted | £250 to £450 |
| Enlarging an existing hatch | £200 to £400 |
| Loft light and switch | £80 to £150 |
A quote that boards straight onto joists over 270mm of insulation is cheaper because it is doing less. It also crushes the insulation, which is the thing you paid for.
What moves the price
- Raised or direct. Raised boarding over legs costs more and is the only correct answer where insulation is deeper than the joists.
- Area boarded. Most people board a third to a half of the loft, not all of it.
- Hatch. Enlarging a 562mm hatch is common and adds £200 to £400.
- Access and roof type. A trussed roof means boarded bays rather than open deck, and takes longer.
- Lighting and a switch at the hatch.
What the job involves
Modern insulation is deeper than the joists it sits between, usually 270mm against joists of 100mm. Boarding straight onto the joists crushes the insulation to a third of its depth, which costs you heat and can cause condensation in the roof space. Raised boarding solves it: a system of legs or a timber counter-batten lifts the deck clear, the insulation stays fluffed, and there is a ventilation gap above it.
Questions about loft boarding
Will boarding my loft cause damp?
It can, if the boards sit directly on the joists and squash the insulation. A raised deck with an air gap above the insulation and clear eaves ventilation avoids it.
How much weight can a boarded loft hold?
Ordinary ceiling joists are not designed for storage loading. As a rough guide treat a domestic boarded loft as light storage only, and get advice before storing anything heavy or concentrated.
Do I need building regulations approval?
Not for boarding out for storage. You do the moment it becomes a room, which brings in floor strength, escape routes, fire protection and head height.